As the sun set on the last day of the Olympic Games, a group of British soldiers working at the Olympic Park prepared to finish their tour of duty. “I don’t want my London experience to end!” said one as she watched spectators file merrily out of the park.

It’s a sentiment that echoed across Britain, and beyond, as the Olympics came to a close. “There’s nothing to watch now!” says 80-year-old Dorothy Aylott, strolling by London’s Tate Museum a few days after the Games finished. She and two friends, Pat Stickley and Valerie Weatherhead, both 82, were on their weekly visit to the metropolis from the suburb of Chessington. “I thought it was great,” says Stickley. “We feel something’s missing.”

The press has dubbed this low the “post-Olympic withdrawal.” On Tuesday, the Times of London ran an editorial listing “the top dozen” symptoms of the ailment, which includes saying everything twice, “first time in French.” Others have proposed possible cures: on Monday, Daily Telegraph columnist Allison Pearson begged for an Olympic patch that “provides a steady controlled dose of euphoria throughout the day.” Even those with no obvious connection to sports or London have taken up the lament. “It’s like the day after Christmas,” wrote Jessica Morgan of Los Angeles–based fashion blog Go Fug Yourself, which tracked the Olympic stylings of the royal family during the Games. “It feels like the end of fun. Forever.”

So why did the Olympics give so many people such a boost? There are, of course, the obvious answers: national pride swells whenever a country’s athlete can swim faster, jump higher or pedal more furiously than anybody else on the planet. For Britain, there is the added sense that — despite much pre-Olympic doom mongering in the press — London hosted a successful Games. (“Didn’t We Do Well!” crowed the bellwether tabloid Daily Express, the day after the Games ended, striking a note of self-congratulation that may come easily to the Express, but not to the British at large.)

But the true power of the Olympics, social psychologists say, lies not in medal counts and flag waving, which every participating country indulges in, but in the feeling of community those activities create. “During the Olympics, we get the sense that we’re all in it together,” says Stephen Reicher, professor of social psychology at the University of St. Andrews. As a consequence, he says, we’re more likely to help and support others, and expect others to do the same. “That leads to an optimism, a confidence, a belief that you can deal with the challenges of life.” As many have noted, this led to unusual displays at the Olympic Park, including spontaneous high fives between strangers, endless friendly banter from park volunteers and even a group of normally staid London bobbies striking Usain Bolt’s signature lightning pose en masse for giggling tourists.

Social psychologists call this bubbling collective excitement “effervescence.” Émile Durkheim, the 19th century French sociologist who coined the term, wrote that when people enter this state, “the vital energies become hyperexcited, the passions more intense, the sensations more powerful,” adding that man “feels somehow transformed and in consequence transforms his surroundings.” That certainly sounds like the mood inside Olympic venues, where the jubilant roar from the crowd regularly exceeded 100 decibels and topped out at 140 — the equivalent of a jetliner taking off — after British cyclist Victoria Pendleton pedaled to gold in the velodrome.

Now that Britain has experienced two weeks of nonstop effervescence, it wants to figure out how to bottle it for an inevitable rainy day. There have been talks of mass volunteerism to capitalize on the goodwill generated by the unpaid Games Makers. Others have pushed for expanding sports programs in schools.

But in light of social psychology, it would appear that simply doing things together is the important thing. “It doesn’t matter whether it’s in a knitting club or a bridge club or a running club,” says Reicher. “Participating together with others, working together with others, having a sense of ‘us-ness’ with others is good for our health and well-being.”

Unfortunately, this may be the one thing contemporary society is not well equipped to foster. And when it does, it can go awry. Last year in London, swaths of the city were wracked by riots as marginalized communities felt a sense of effervescence in achieving their collective goal: sticking it to the police. And a year later, the cracks are already showing in the post-Olympic discourse of unity, as debates about the educational background of British Olympic athletes expose old divides in British society.

Still, despite the pitfalls, some Brits seem to have already intuited the valuable lessons that might be drawn from the Games. The octogenarian ladies from Chessington not only enjoy days out in London together — they also have joint athletic pursuits as well. “We swim once a week,” says Weatherhead when asked about her friends’ interest in sports. “Though unfortunately not to an Olympic standard.”